Showing Kids How Plants Drink with Colour | Carnation Test
Transpiration – such a big word and a complicated term, but one that is so exciting to experiment with and to show your Brisbane Kid the process of how plants feed. By following this simple science experiment, your child can see for themselves how plants suck water and nutrients out of the soil and surrounding moisture to feed. The water and its nutrients are then sent through the plants “vein” system out into the petals and leaves. The results are nothing less than magical; as you change a white based flower or vegetable into any colour you like.
- Food colouring
- White flowers (carnations, roses and gerberas work best) or wombok cabbage
How to change the colour of flowers
Fill a glass of water with 5 drops of food colouring.
Take the stem of your flower or base of your cabbage leaf and cut off the end.
If you are using cabbage, cut the leaf in half through the middle lengthways and place base first into the coloured water. If you are using a flower, carefully slice the stem at the base length ways about half a centimetre and then place into the coloured water (this will aid in the plant sucking up the water).
Leave and watch the magic happen.
Alternate Experiment: Super Plant – Extra Magic
Take a white flower (carnations work great for this) and cut the stem vertically in two about 5cm long.
Using two glasses, fill one with coloured water and the other with different coloured water.
Take the flower and place one part of the cut stem into one glass and the other half into the other glass.
Place your glasses against a wall to support the flower – you may need to use Blu-Tac to stick the flower to the wall so it doesn’t fall over. Make sure the flower stem is in the water.
The magic will happen soon and you will have a two toned flower!
Explaining this process:
Ask your child why they think the flower changes colour and what is happening. You may be surprised by how much they know.
Here is how my children responded –
3yr old – “The flower is sucking that colour water.”
5yr old – “Oh wow its magic!! The flower is drinking the water and it changes colour.”
7yr old – “Plants are like humans, they need water to live. And they get the water through their stems. The cabbage has veins like we have. You can see the colour in its veins. The flower changes colour because the water has been coloured. Would we change colour if we drank blue water?!”